The present invention relates to an electronic book device by which a user can read an electronic document as if he or she was reading a printed book and, more specifically, relates to an electronic book display control device capable of reproducing electronic image data of a document, and a data structure and a reproduction display device capable of changing the display image contents at a high speed.
Prior arts relating to electronic book display control methods for changing display scenes just like turning pages of a printed book are disclosed in Japanese Laid-Open Patent Publication No.64-86191 and 2-181864. The former provides an electronic book device that has a control portion including a memory for storing two kinds of images, two selectors and a speed controller and can changeover a display image just as it turns a page of the book by presenting a next image on a part of a display area of a preceding image and by gradually increasing the next image and finally displaying a full image on a full screen. The latter provides a user-friendly electronic book device that has a book-contour display portion to display a contour image of the book and open the book when the user points a position on a fore-edge of the book and giving the user a feeling of reading the book by changing the thickness of the fore-edge of the book displayed on the display portion.
Japanese Laid-Open Patent Publication No.5-53726 describes a display tablet device that detects a trace, a direction and a speed of movement of a pen on a display screen by an input detector.
With a display device for displaying a plurality of data-recorded sheets such as data of plural document pages and image data of a image filing device, one may often change in succession display images to search objective data. In this instance, if display data is fully displayed every time, high-speed changeover of data images cannot be realized and the retrieving efficiency is decreased. In view of the above, an image filing device disclosed in Japanese Laid-Open Patent Publication No.1-269174 performs the retrieval of objective data in a data image memory in such a manner that a part area of data being displayed on the screen is designated first by the user, the data is then retrieved from the specified data area in the image data memory and displayed by repeating the above cycle of retrieval operations to find the objective data. Japanese Laid-Open Patent Publication No.4-120670 also discloses such a method that original image data and contracted data of the original image are stored in a memory device, contracted data is read in retrievaling and displayed in succession like turning pages at a high speed.
However, methods disclosed in Japanese Laid-Open Patent Publications No.64-86191 and No. 2-181864 have such drawbacks that the display is controlled according to the data calculated by the speed controller and hence it is difficult to flexibly change the speed of display in accordance with the type and contents of data stored in a memory. For example, it is impossible to change a display image just as turning of a page of the book in spread state. The both systems have the limit to its display control and cannot realize, in this sense, a display that is so called friendly to users.
The above systems can turn pages at a specified display speed calculated by its controller and hence cannot control the display speed in accordance with the contents of data to be displayed or skip a page.
The system disclosed in Japanese Laid-Open Patent Publication No.5-53726 involves such a problem that it requires, besides display memory, the provision of an additional image-memory whose capacity is two times larger than the display area.
The system disclosed in Japanese Laid-Open Patent Publication No. 1-269174 has no consideration of a method for storing display data necessary for changing page images at a high speed and hence requires time for turning pages.
The system disclosed in Japanese Laid-Open Patent Publication No. 4-120670 has to store a large number of data because the contracted images preliminarily registered include redundant data.
Furthermore, the above systems cannot be adapted to turning pages of a recent available document whose pages may include various kinds of data such as characters, pictures, audio signals and moving pictures on one page.
To solve the above problems involved in the prior arts, the present invention is intended to provide a display changeover control portion including a table for storing column information necessary for turning pages and means for selecting addresses of a display preparation image data storage portion and image data of a current display page and a next display page from the column information, which can control the display speed flexibly in accordance with image data to be displayed, realizing changeover of display images just as turning pages of a printed book.
To solve the problem involved in the prior arts, the present invention also aims at saving of an image data memory capacity to a half the memory capacity of the prior art devices by providing a data latch for reading image data from the display image data storage portion and temporally storing it.
Another object of the present invention is to realize high-speed turning of pages by storing information of a display image sequence in a high-speed read-only memory.
A further object of the present invention is to provide a data structure and a reproduction display device that can perform high-speed changeover of display images.
An electronic book display control device according to the present invention comprises a central processing unit (CPU) for controlling the whole device, an image data storage portion for storing therein the contents of the book as image data, an image data control portion for receiving the image data and performing required control, a display preparation image data storage portion for storing image data of a page being displayed and image data of a page to be displayed next, a display portion for displaying thereon information concerning the image data and information concerning the operation of the electronic book, a page-turning data storage portion for storing data displayed on the display portion at a specified time for a page-turning period, a column information storage table for storing column information of the page turning data, and a display changeover control portion including a selecting means for selecting an address of the display preparation image data storage portion and image data on the page being displayed and the to be displayed next according the column information. This device can therefore turn pages (display image) just as turning a printed book by flexibly controlling a current image and a next image according to the column information.
An electronic book display control device according to the present invention is also featured by storing the column information table in the image data storage portion and can thereby realize turning of pages in accordance with the contents of the book.
An electronic book display control device according to the present invention is further featured by storing the column information table in a ROM or a rewritable ROM other than the image data storage portion and can thereby realize high-speed and flexible turning of pages.
An electronic book display control device according to the present invention is further featured by pairing the column information table with image data and can easily control image data on the page-by-page basis, thus realizing natural turning of pages of the image data like book.
An electronic book display control device according to the present invention is further featured by reading the column information into a column information storage table based on information observable on an input portion and can thereby display pages of the image data in accordance with the characteristics of the user and the story of the book.
An electronic book display control device according to the present invention comprises a central processing unit (CPU) for controlling the whole device, an image data storage portion for storing therein the contents of the book as image data, an image data control portion for receiving the image data and performing required control, a display preparation image data storage portion for storing image data of a page being displayed and image data of a page to be displayed next, a display portion for displaying thereon information concerning the image data and information concerning the operation of the electronic book, a page-turning data storage portion for storing data displayed on the display portion at a specified time for a page-turning period, a column information storage table for storing column information of the page turning data, a display changeover control portion including a selecting means for selecting an address of the display preparation image data storage portion and image data on a page being displayed and a page to be displayed next according the column information, and a data latch for reading a part of the image data from the display image data storage portion and temporally storing the data therein. This device can therefore realize saving of the capacity of memory for display preparation image.
An electronic book display control device according to the present invention is also featured by storing a difference between data of the page being displayed and data of the page having been displayed just before the current page in the column information storage table, thus realizing further saving of the capacity of memory for display image.
An electronic book display control device according to the present invention is further featured by the providing an input selector and an output selector for selecting a memory at input and output portions of the display preparation image data storage, thereby realizing high-speed display of an image.
An electronic book display control device according to the present invention is further featured by the fact that image data is divided and stored in the image data storage portion so as to be readable in the order necessary for turning pages, thus making it possible to preliminary read data to be displayed and thus achieving display of image data of a story with a saved memory capacity.
A reproduction display device according to the present invention is used for reproducing and displaying element data in units of reproduction of the device, wherein a partial data of the element data includes an identifier for high-speed reproduction and, when a request for a high-speed reproduction signal is given, the partial data is reproduced and displayed successively. This eliminates the necessity of preparing data specially designated for high-speed reproduction in units of reproduction, thereby realizing the reproduction in units of high speed reproduction by using a saved memory capacity. For electronic documents, a unit of data to be displayed is composed of data of each page image, so pages can be fast turned over on the display screen by using a reduced amount of data in a recording medium.
A reproduction display device according to the present invention is also featured by the fact that a partial data of the element (object) data for reproduction is differently compressed from the other data so that it can be reproduced at a further increased speed and achieve more high-speed turning pages than the electronic book. The element data is preferable to be any of the following types:
Namely, the element data is image data, wherein a part of the data is a significant bit image produced by a part of bits of each pixel, a part of the data is a part of each divided bit-plane image, a part of the data is a thinned image produced by thinning pixels and a part of the data is divided image of an original image. The element data may also be video data, wherein a part of the data is a representative frame image selected from the video data.
A reproduction display device according to the present invention is featured by the fact that the element data is image data or video data and a ratio of the partial data to be displayed is changeably set, thereby making it possible for the user to reproduce and display the data at any desired speed even in a high-speed reproduction mode and to easily conduct retrieval of the display data.
A reproduction display device according to the present invention is featured by further provision of condition setting means for presetting at least one of conditions: data type (classification), data size of the element data and position information for a reproduction unit, wherein element data to be reproduced in the high-speed reproduction mode can be selected according to the preset conditions. This makes it possible for the user to omit the unnecessary or undesired data from the scope of reproduction, thus achieving an improved retrieving efficiency and an improved level of the display operation control.